Two Indian companies - Bharat Petroleum Corp Ltd and Indian Oil Corp - will together hold a 100 percent stake in the exploration phase for Onshore Block 1, ADNOC said in a statement.

The Indian firms will invest up to 626 million dirhams ($170 million), including a participation fee, to explore and appraise oil and gas in the block. If successful, the consortium will be able to develop and produce any discoveries with an option for ADNOC to hold a 60 percent stake in the production phase.

The agreements, which have a term of 35 years, conclude Abu Dhabi's first-ever competitive block bid round, ADNOC said.

"The onshore exploration block awarded to the Indian consortium will target, specifically, the conventional oil and gas opportunities in the area," ADNOC said.

The Onshore Block 1 area also covers the separate Ruwais Diyab Unconventional Gas Concession, where France's Total has the exploration rights for tight gas in the Diyab formation.

ADNOC has awarded Offshore Blocks 1 and 2 to Italy's ENI and Thailand's PTT Exploration and Production Pcl ; Onshore Block 3 to US-based Occidental Petroleum; and Onshore Block 4 to Japan's Inpex Corp .